Advanced High-Energy All-Solid-State Hybrid Supercapacitor with Nickel-Cobalt-Layered Double Hydroxide Nanoflowers Supported on Jute Stick-Derived Activated Carbon Nanosheets

Developing efficient, lightweight, and durable all-solid-state supercapacitors is crucial for future energy storage systems. The study focuses on optimizing electrode materials to achieve high capacitance and stability. This study introduces a novel two-step pyrolysis process to synthesize activated carbon nanosheets from jute sticks (JAC), resulting in an optimized JAC-2 material with a high yield (approximate to 24%) and specific surface area (approximate to 2600 m2 g-1). Furthermore, an innovative in situ synthesis approach is employed to synthesize hybrid nanocomposites (NiCoLDH-1@JAC-2) by integrating JAC nanosheets with nickel-cobalt-layered double hydroxide nanoflowers (NiCoLDH). These nanocomposites serve as positive electrode materials and JAC-2 as the negative electrode material in all-solid-state asymmetric hybrid supercapacitors (HSCs), exhibiting remarkable performance metrics. The HSCs achieve a specific capacitance of 750 F g-1, a specific capacity of 209 mAh g-1 (at 0.5 A g-1), and an energy density of 100 Wh kg-1 (at 250 W kg-1) using PVA/KOH solid electrolyte, while maintaining outstanding cyclic stability. Importantly, a density functional theory framework is utilized to validate the experimental findings, underscoring the potential of this novel approach for enhancing HSC performance and enabling the large-scale production of transition metal-based layered double hydroxides. This study presents a novel all-solid-state hybrid supercapacitor, featuring a unique electrode material synthesized from jute stick-derived activated carbon and nickel-cobalt-layered double hydroxide nanoflowers. Demonstrating impressive performance metrics, including a specific capacitance of 750 F g-1 and an energy density of 100 Wh kg-1, this research paves the way for efficient and sustainable energy storage solutions.image